Duchenne muyscular dystrophy is caused by a mutation on the X chromosome, so a male gets it from his mother's X, if she is a carrier. The male child gets a Y and no X from his father, so the disease is always transmitted through the X from the mother. If a female gets Duchenne muscular dystrophy she has to have two X chromosomes, one from a carrier mother and another from from an affected father. This is virtually impossible because most males die before childbearing age and there is no way a female child can get an X from a man who does not live long enough to procreate. About eight percent of carrier women do show some muscle weakness, but they do not have the disease.
What alleles do the parents have? If the parents are both Homozygous recessive the answer is 0%. If one is homozygous dominant it doesn't matter what the other one is, the answer is 100%. if the are both heterozygous the answer is 75%
Answer:
Genotypic ratio = 16 WwDd: 0
Phenotypic ratio = 16 white, disk shaped fruit : 0 yellow, sphere shaped fruit
Explanation:
This question involves two different genes coding for fruit color and fruit shape respectively. The allele for white fruit color (W) is dominant over yellow fruit color (w) and disk shaped fruit (D) is dominant over sphere-shaped fruit (d).
According to this question, If a squash plant pure-breeding for white, disk shaped fruit (WWDD) is crossed with a plant pure breeding for yellow, sphere shaped fruit (wwdd), the following gametes will be produced by each GAMETE:
WWDD - WD, WD, WD, WD
wwdd - wd, wd, wd, wd
Using these gametes in a punnet square, all of the offsprings will have genotype WwDd, which is phenotypically white and disk shaped fruit.
The genotypic ratio is 4 WwDd: 0
The phenotypic ratio is 16 white, disk shaped fruit : 0 yellow, sphere shaped fruit.
Answer:
A it investigates the super natural.
Answer:
a. When a fetus is 13-15 weeks old
Explanation: is correct